Olympus EPOCH 650 User Manual page 188

DMTA-10055-01EN, Rev. A, February 2015
Olympus transducer part number A430S-SB with a frequency of 2.25 MHz and an
element size of 15.88 mm × 15.88 mm (0.625 in. × 0.625 in.). The transducer is mounted
on a 45° wedge, part number ABWS-6-45. An Olympus NAVSHIPS carbon-steel
calibration block, part number TB7567-1, is used.
Calibrating for Distance
The NAVSHIPS Block, which has six No. 3 side-drilled holes at various depths (see
Figure 9-35 on page 185), produces echoes at various depths on the screen in 6.35 mm
(0.25 in.) increments, which are used for depth distance calibration. This allows you to
calibrate for various inspections ranges up to 69.85 mm (2.75 in.). For this sample
calibration, the side-drilled holes at depth 12.5 mm and 38 mm (0.5 in. and 1.5 in.) are
used.
For information on distance calibration with other standard calibration blocks, see
"Common Angle Beam Calibration Block Diagrams" on page 181.
If the EPOCH 650 is set to work in metric units, the calibration process is exactly
the same, except that the entries are in millimeters rather than inches.
To calibrate for depth distance
1. Choose Basic > Range, and then set the value to 100 mm (4 in.). This ensures that
the echoes from the block are visible on screen.
2. Select Auto Cal > Type = Depth.
3. Couple the transducer to the calibration block and move the probe backward and
forward to maximize the reflection from the side-drilled hole at depth 12.7 mm
(0.5 in.).
Press PEAK MEM to use the Peak Memory feature to help find the peak of the
signal.
176 Chapter 9